The three are molluscs, from the gastropod class. The main difference between the slug and the other two is that it doesn’t have an outer shell – or it has a very small shell. Caracol and caramujo are synonyms in several regions of Brazil, but in popular language, caracol generally refers to terrestrial gastropods, and caramujo, to aquatic ones. Slugs can live both on land and in the sea. Together, these three little animals add up to about 75,000 species. In addition to being numerous, they are ancient inhabitants of the Earth: there are fossil records of gastropods from around 500 million years ago. There are between 30 and 40 families of slugs, against 400 of snails and snails, according to biologist Luiz Ricardo Simone, from the Museum of Zoology at the University of São Paulo, author of the book Land and Freshwater Molluscs of Brazil (“Terrestrial and Freshwater Molluscs of Brazil”). You may not like the gunk they leave behind, but without them, environmental imbalances can occur.
MY NOTHING SOFT LIFEDespite being hermaphrodites and slimy, gastropods live without salt
INNER BEAUTY
The body of land slugs has three main parts: head, foot and visceral mass, which is covered by a kind of skin, the mantle. From the head, four tentacles come out, all retractable: two are the base of the eyes and two are used for touch and smell. The underside of the body of snails is the same as that of slugs
UNDER THE SNAILS
Snails and snails are born with a protoconch, which already contains all the layers of the shell of the
adults. As it grows, a gland in the mantle secretes the three layers that make up the material:
Periostracum: Outermost part, rich in conchiolin, an organic matter. Protects the shell from corrosion from the environment
Ostrachus: Intermediate layer, made of calcium carbonate, which gives hardness to the shell
Hipostrachus: It is closest to the body. It is responsible for repairing any fracture suffered by the shell
FRESH HEAD
Depending on where they live, gastropods breathe in different ways. While marine forms use gills (like fish), land forms have lungs and perform gas exchange through a hole on the side of the head, called pneumostome. As these species have very
thin, they also absorb oxygen directly through it
MINIMUM SPEED
To move, slugs and snails rely on the help of a kind of mucus, secreted by a gland located in the belly. This slimy substance is important because it helps the animal glide. They move by making wave-like movements, like snakes and worms. Smaller animals (up to 1 millimeter in length) also rely on the help of thousands of cilia located on the belly, which function as a succession of little feet.
Understand how slugs and snails move:
1. To move around, the first step is to lift your head at an angle of 20 to 30 degrees from the floor
2. Then, the animal stretches the rest of its body, and the parts that come off the ground alternate along the slug’s body, until it starts all over again
CROSS-SEX
Most land gastropods are hermaphrodites: the same animal has a penis and a vagina, but needs a partner to breed. During mating, there is cross fertilization, in which one sperm transfers to the other and vice versa. See how the leopard slugs fuck radically (limax maximus):
1. A slug that wants to mate releases mucus with a “special flavor” that announces to fellow slugs that it is in the mood
2. The two slugs then climb onto a branch and wrap around each other, releasing a thread of mucus.
up to 40 centimeters
3. Rolled up, the two go down the thread and each one places the penis (which was “hidden” under the
cloak) out
WITH THE TONGUE IN THE TEETH
To eat, gastropods use the radula, an organ similar to the tongue, with thousands of protuberances that resemble human teeth. The tip of the radula scrapes the food, and the «teeth» on the surface cut it. Gastropods face everything when it comes to eating: some only eat small plants, others prefer matter
rotten organic matter and there are also carnivores, which eat insects, other molluscs and even small fish
OH MY SALTS
Many children have already done the bad thing: they threw salt on the slug to see it melt. This happens because her skin is very thin and permeable. By a chemical process known as osmosis, salt «sucks» the water existing in the animal’s body, causing it to lose a lot of fluid and die of dehydration.
APPEARANCES DECEIVE Among the 400 families of snails and snails, there are everything from delicacies to dangerous animals
DO GOOD…
He’s a land snail of the Helicidae family, and like all molluscs, he’s pretty disgusting. But, as it is herbivorous and feeds only on fruits and vegetables, snails have become one of the most refined delicacies in the world. Some breeders let the animal fast and then feed them with water, aromatic herbs and even white wine! A kilo of its meat – which has between 120 and 150 animals – costs almost 100 reais
…AND EVIL
Some snails of the family Planorbidae are hosts of the worm responsible for schistosomiasis. Another nasty gastropod is an African snail (Achatina fulica), a species introduced in the 1980s as an alternative to escargot. Contact with its mucus can cause disturbances in the nervous system, perforation of the intestine, abdominal bleeding and even death of the patient.
Read too:
–What is the difference between octopus and squid?
– What is the difference between a bee and a wasp?
– What is the difference between a seal, a sea lion and a walrus?